1. Field of the Invention
The present invention relates to a lateral pipe lining method and a lateral pipe lining apparatus, and more particularly, to a lateral pipe lining method and a lateral pipe lining apparatus in which a flange formed on one end of a flexible tubular resin-absorbing material impregnated with a curable resin is brought into close contact with the periphery of a lateral pipe opening of a main pipe and eversion pressure is applied to the lateral pipe lining material to evert and insert the lateral pipe lining material into the lateral pipe in order to line the lateral pipe with the lining material.
2. Description of the Related Art
When pipelines such as sewer pipes buried underground have degraded, there is known a pipe lining method in which the pipeline has its inner surface lined and repaired without the pipeline being dug up from underground.
In this pipe lining method, a tubular lining material comprising a flexible tubular resin-absorbing material impregnated with a curable resin, the outer circumferential surface of which has been coated with a high-airtight film, is inserted into the pipeline while being everted using fluid pressure. The tubular lining material is pressed against the inner circumferential surface of the pipeline by fluid pressure, and is then heated to cure the curable resin impregnated in the material and line the inner circumferential surface of the pipeline.
Such a method can be applied even to the lining of a lateral pipe that branches from a main pipe. When lining the lateral pipe, a flange formed on one end of a tubular lateral pipe lining material that is housed in a pressure bag is positioned on the head collar of a work robot guided into the main pipe. The work robot is driven to bring the lateral pipe lining material so that the flange thereof comes into close contact with the periphery of the lateral pipe opening of the main pipe. When a pressurized fluid such as a compressed gas or a liquid under pressure is fed into the pressure bag, the lateral pipe lining material is subjected to this pressure, and is inserted into the lateral pipe while being everted. When the material is completely everted and inserted along the entire length of the lateral pipe, the lateral pipe lining material is pressed against the inner circumferential surface of the lateral pipe and heated to cure the thermosetting resin impregnated in the lining material. The inner circumferential surface of the lateral pipe is thus lined by the cured lateral pipe lining material.
Since the lateral pipe lining material is everted and inserted into the lateral pipe by feeding a pressurized fluid to the pressure bag, any leakage of the pressurized fluid may result in the pressure being inadequate, and the lateral pipe lining material becoming less readily everted and inserted. In particular, if the lateral pipe lining material is not reliably positioned in the pressure bag, the area at which the lateral pipe lining material is connected to the pressure bag will cease to be airtight, making it difficult to evert and insert the lateral pipe lining material.
To improve airtight connection between a pressure bag and a lateral pipe lining material, Japanese Laid-open Publication No. H04-355115 proposes that a removable tube that is shorter than the lateral pipe lining material and that can be removed therefrom is provided, and the one end of the removable tube is temporarily fixed near the flange of the lateral pipe lining material with the other end thereof being secured to the pressure bag. The lateral pipe lining material is reliably everted and inserted because pressurized fluid cannot leak outside from where the removable tube is temporarily fixed.
Japanese Laid-open Publication No. 2008-168468 discloses that a tubular sealing member comprising a metal or a hard plastic is integrated with the flange of the lateral pipe lining material, and an annular elastic body is mounted between this sealing member and a cylindrical member fixed to the head collar of the work robot. This elastic body produces an airtight seal between the periphery of the flange of the lateral pipe lining material and the pressure bag, allowing the lateral pipe lining material to be everted and inserted into the lateral pipe without pressurized fluid leaking out.